Lead-in for radio apparatus



June 4, 1929. A J, A, RQSTRON 'I 1,715,952

LEADJN FOR RAMO APPARATUS Filed. Oct. l1, 1924 2 Sheets-Sheet l` June 4, 1929. J. A. 4RosTFzoN 1,715,952

LEAD-IN FOR RADIO APPARATUS Filed oct. 11, 1924 2 Sheets-Sheet 2 \Y l?? vente?.

l oje/i $.15.' gfs'itry'on' daz'zigys tof Patented June 4, A1929.

UNITED STATES d'OSEPI-I A. ROSTRON, OF CAMBRIDGE, MASSACHUSETTS.

LEAD-IN FOR RADIO APPARATUS.

Application led October 11, 1924. Serial No. 743,021.

This invention provides an improved leadin for radio apparatus. More particularly it relates to the connection between radio apparatus located indoors and connectedto an outside antenna. This may receive or transmit, or both, as is well understood, but asin the greater number of instances the principal 'use is for reception, the description herein using the term reception for the indoor apparatus will serve for both, without signifying that the invention is limited to such. It is an object of the invention to provide for the reception of the waves which are impressed upon the antenna without having any wires or other conductor of electricity enter the house from the outside. It is another object to provide for the reception without there bein any opening either through the wall or t rough a window. It is another feature, resulting from the invention, that a lightning arrester is provided as a part of the apparatus without the need for a separate device being installed for that purpose. It is also observed that the use of the apparatus of the invention sharpens the tuning of the reception apparatus, and clarifies the reception so that a .voice which is muddy or unclear when heard through ordinary antenna connections becomes clear when the reception is through the apparatus of the invention.

These objects, and the other advantages which are characteristic of the invention, are attained by placing plates of metal on opposite sides of the glass in a window of the apartment, arranged to co-act as a condenser. While various materials and arrangements may be used, the particular embodiment of the invention which is at present preferred provides a pair of metallic disks and means whereby they may be mounted facing each other and pressing together with the pane of glass intervening. The lead-in wire coming down from the antenna is connected to the outer of these; the reception apparatus is connected to the inner of them.

In one embodiment of the invention illustrated herein each disk is of stiff material and is supported from the sash of the window by a spring bar attached to it through an insulating porcelain collar. The attachment of the out of doors spring bar to its collar forms a convenient place for the attachment also of a wire leading to ground.

Lightning coming down from the antenna linds no occasion to pass through the window glass, and a discharge in that direction is discouraged by the fiat and large nature of the condenser surfaces; but a discharge can occur readily by leaping across through the airI over the narrow porcelain exposure to the said ground wire, and a high potential thus can continue its journey to earth without entering the house. l f

In another embodiment shown in the accompanying drawings the disks are supported by the windowpane itself. In this arrangement there is a suction device which grips the surface of the glass; and being suitably connected to the metallic disk this device holds the latter' lirmly' against the pane. There is also a lightning arrester and ground wire outside of the building supported by the suction element, which is suitably insulated from the condenser elementV to prevent leakage of the normal currents from the antenna and yet is adapted to dischargeany lightning or gathering of high potentialv preparatory to lightning.

Moreover, the condenser elements may take the form of thin metallic foil, and be supported by their natural adhesion to the glass, or be made to adhere b y an adhesive, as in another illustrated form.

It is intended that the patent shall cover, by suitable expression inV the appended claims, whatever features of patentable novelty exist in the invention disclosed.

The accompanying drawings illustrate an embodiment of the invention, in which Figure l is an elevation, as seen from outside the building, of reception apparatus embodying one form of the present invention' Figure 2 is an elevation, partly in section, on line 2 2 of Figure l, the parts outside the window being shown in full lines;

Figure 3 is an elevation like Figure l, showing a modification;

Figure 4 is an elevation of the same, partly in section on line 4 4 of Figure 3,A the indoor parts being in full lines; and

Figure 5 isV an elevation in section, showing another modification.

Referring to the drawings, 10 and 20 respectively are disks of metal, which. may for example be 8 inches in diameter arranged on opposite sides of a window pane A. This may be any ordinary window pane which may happen to be foundin the apartment where the radio receiving apparatus is to be used; or an existing pane may be replaced by a pane o'f thin plate glass with improved strength of electrical transmission. Each disk has a central post 11, on which is a. ring of porcelain 12, held by a washer or nut 13 which is on the central post and is sligthly larger than thc porcelain collar in diameter. Against each ot these may be attached by binding nut 11.4' any suitable form of device, indicated at 15 as a Fahnstock connector, for receiving the leadin wire 16 which comes down trom the antenna or the wire 16a leading to the reception apparatus. The porcelain collar is held between the semi-circular jaws 418 and 181 of an encircling support clamp, a continuation 18b of one jaw of which runs radially past the extent of the disk to the window sash 19 to which it is adapted to be fastened as at 20. At the lower junction of these semi-circular jaws the screw 21 affords a convenient place for the connection of a wire 22 leading to ground outside ot' the building. This leaves metallic parts, viz, the clamp 13 and the support 18, adjacent to each other, with a slight gap between them, across which lighting, coming down from the antenna can readily pass and by wire 22 reach the earth, but which ordinary radio impulses cannot jump.

In Figures 3 and 4 a modification of the apparatus is illustrated whereby the disks 10nl and 20L are held against the window pane A without any rigid arms engaging the sash 19. Each disk has a central hole 24: bridged by a bent strip 26 of metal to which is clamped the antenna wire 16 or the lead 16au to the reception apparatus. A .bolt 11a which passes through the bridge piece, has fixed on its head under the bridge, a rubber suction cup-disk 28 which can be pressed against the glass and which will adhere thereto by virtue of the partial vacuum formed in its cup. On the shank of the bolt 11a, of the inside member, a wire clip 15 is secured by a binding nut 14. On the outside bolt 11a there is provided next to the bridge a layer 30 of insulation, such as .mica, against which is arranged a wire clip 15u having a hole larger than the bolt so that it can be hushed by another insulating strip 32 and thereby kept from contact with the bolt. To this clip 151 is attached the ground wire 22. Another wire clip 15 is applied against the other layer of insulation and all are clamped to the bridge piece by a binding nut 14. The wire from the antenna is held by this last mentioned clip. Radio impulses pass from the wire 16 through the clip 15 and bolt 11a to the bridge piece 26 and thence to the disk 10a. Lightning coming down the wire 16 jumps the gap between the two clips 15 and 15a and passes on to earth through the ground wire 22.

mimosa The plates 10 and 2O co-act as a condenser, to pass through the pane the radio transmissions which come to plate 10 from the antenna, in the case of reception, or to send out transmissions originating in the indoor apparatus. Connection from the plate 20 to the indoor apparatus for operation, and to the window sash for supporting, may be similar to those of the plate 10.- Thus the radio impulses of the outdoor antenna are brought into the house without there being any opening in the window or any direct conductor connection between the outside and inside of the house. The described apparatus constitutes a lightning arrester because it provides an easier path for lightning to the ground than by going through the reception apparatus or even to the interior plate 20. And it has been observed that under ordinary working conditions the r'eception is clarified where the device is used, and the tuning made more sharp thereby.

In the claims the word antenna is used in its generic sense as applying to any sort of outside apparatus for picking up radio impulses, and may include a loop if so arranged.

Although the apparatus is illustrated in a form which is convenient for commercial sale, consisting` of disks 10 and 2O which are normally pressed firmly on the glass by spring supports, but which are independent-ly stiii and can stand up even though there be no glass between them, it will be understood that. the principle of the invention may be applied in other ways, as, for example, as shown in Figure 5 by 'coating the outside and the inside of a window pane A with metallic foil, respectively 10b and 20h. These extremely thin plates are suitably connected respectively with the antenna and with the indoor apparatus. This connection is illustrated as being by light spring conductor arms 18c supported respectively on the outside and the inside of the wooden sash of the window, and bent to press against the tin toil plates 10b, 201. These arms are properly insulated from the window sash and are provided with binding clips 15b, for attachment of the wires 16 from the antenna, 16a to the reception apparatus, and 22 to the ground.

In the case last mentioned the metallic foil strips are supported by their adhesion to the glass, which maybe by natural aiiinity or adsorption, or may be with aid of an added adhesive substance. In the cases first described the metallic disks are supported by their respective arms which are mounted on the window sash, or by the vacuum disks, both of which supports are of a springy nature each pressing its plate firmly upon the glass and holding it there rigidly with elastic pressure. Or, if desired, the metallic disks may be glued to the glass and the antenna wire and wire leading to the reception apparatus soldered to their respective disks, and provision made for support of the ground wire adjacent to one of the disks with suitable gap intervening.

I claim as my invention:

l. A lead-in for radio apparatus compris* ing a condenser, one element of which is adapted to be connected to an outdoor antenna and the other to indoor apparatus; these elements being adapted to be arranged in a window of a building and to be mounted with glass of the window between them and comprising the cli-electric of the condenser, whereby outdoor electrical impulses are transmitted to the indoor apparatus.

2. A lead-in for radio apparatus comprising a pair of condenser plates and means 'whereby they are mounted in a window of a building in opposition on a pane of said window, one being adapted to be connected to the outdoor antenna and the other to indoor apparatus, whereby outdoor impulses in the antenna are communicated to the said indoor apparatus.

3. A radio lead-in comprising a pair of condenser plates, secured so as to co-act on opposite sides of the glass in a window o a building, thus connecting the interior of the room electrically with the exterior thereof.

t. A radio lead-in comprising a pair of metallic plates arranged so as to constitute a condenser in the circuit from an outdoor antenna to indoor apparatus, that plate which is connected to the antenna having adjacent to it a metallic element separated from the antenna connection by a small gap and adapted to be connected to the ground these two being adapted to be connected and to co-act as a condenser in the lead-in circuit.

7 A radio receptor system, comprising an elevated electrical capacitative system, a radio receiving or sending equipment located within a habitable enclosure, and a lead connector between them, said lead connector including a condenser, comprising two conductive plates and a dielectric, said dielectric being also a part of said enclosure.

8. A radio signalling system, comprising a radio sending set, a building with a glazed Window in which said sending set is installed, an aerial erected outside of said building and adjacent to it and a lead in connector between said aerial and said set, said connector comprising a plurality of conductor wires and a series condenser, said condenser comprising two conductive plates fastened to opposite sides of the glass of said glazed window.

Signed at Boston, Massachusetts, this tenth day of October, 1924:.

JOSEPH A.V ROSTRON. 

